• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.199-209
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• 2009

The movement of the caisson used to construct a wharf front can affect functional performance of the port. Sequential movement of caissons at each stage of the construction is essential in the overall design as well as the stability of the port. It is common that back-analysis using the previous measurement is performed to predict the caisson movement, while there is no intensive study on sequential movement of the caissons according to the construction stage. In the study, we analyzed the pattern of the movement of caissons as a port is constructed. To simulate the construction of the port, the finite element method (FEM) is employed. The computed result shows that the caisson moves differently at each construction stage. When the caisson is being installed, the displacement of the caisson takes place mainly in vertical direction. In next stage of filling rocks behind the caisson, the top of the caisson move toward shore, while the bottom moves toward sea, thus rotating the caisson. The maximum rotation of the caisson takes place in the stage of filling rocks behind the caisson.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1032-1039
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• 2022

Evaluating infrastructure's impact on social equity is an emerging area of research in transportation construction engineering. Transportation agencies have been trying to include sustainable development. The three components of sustainable development are environmental protection, social equity, and economic development. Although social equity is one of the essential components of sustainable development, most transportation agencies do not consider this component. The research publications in this area are limited. The principal objective of this study is to synthesize existing studies related to the impact of transportation infrastructures on social equity. This study will also identify social equity indicators, the correlation between social equity and transportation infrastructures and their services, and the impact of transportation infrastructures' on social equity. In addition, this study will identify current issues of social equity and will provide some recommendations. This synthesis study revealed that transportation infrastructures impacted social equity in various ways. Some effects are positive, such as new job creation on the market. Other effects are adverse, such as diminishing socio-economic and environmental degradation. Studies also showed that the current practices evaluated infrastructures' impact on a case-by-case basis. The authors recommend adopting a multi-disciplinary holistic for assessing infrastructure's effects on social equity. The multi-disciplinary fields of study include civil engineers, construction engineers/managers, public policy researchers, environmentalists, and social scientists.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.77-81
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• 2015

The unit price contracting is the standard contracting method for highway projects in the U.S. As a result, state highway agencies have collected a large amount of historical bid data that they can use to determine engineer's estimates for future projects. The estimator must carefully consider various characteristics of a new project such as its location to determine an engineer's estimate as accurate as possible before bid letting. Higher cost estimates can result in the loss of the available budget and lower cost estimates may lead to deferral and delay of projects. The study uses the historical bid data obtained from Iowa Department of Transportation and develops a Geographic Information System (GIS) tool to visually show the variation of unit prices over the map using a spatial interpolation technique. The interpolation map can be used to estimate the unit price of the item at any location across Iowa. This noble method allows the estimator to effectively and fully utilize the historical bid data in a very time efficient manner and determine more accurate cost estimation.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.28-35
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• 2013

The construction industry has introduced the Leadership in Energy and Environmental Design (LEED) rating system to promote objective evaluations of the sustainability of buildings. Three important values to consider when implementing sustainability are the associated environmental, social, and economic impacts. Recently, researchers have begun to investigate the real estate value of LEED certified buildings in terms of the rental cost, occupancy rate, cost per unit area, and resale value in order to better understand the economic benefits of the LEED rating system. However, the economic benefits also encompass economic effects such as the impact of LEED certified buildings on neighborhood real estate values surrounding the certified buildings. This research examines whether the enhanced real estate value of LEED certified buildings in New York City extends to surrounding commercial buildings, utilizing spatial analysis via a Geographic Information System (GIS) and the hedonic pricing method to derive meaningful economic relationships. The results provide practical insights into the economic effect of LEED certified buildings that will be of interest to city officials and planners, as well as the owners, developers, investors and other stakeholders of surrounding buildings.

• Journal of Soil and Groundwater Environment
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• v.24 no.6
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• pp.9-15
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• 2019

Soil dust emitted from large scale construction sites in urban areas has posed a significant health threats to local residents by exacerbating air quality. Water-spraying (moistening) is commonly practiced to lower the dust emission in construction sites, but its long term effectiveness is highly questionable. In this study, the utility of starch and PVA(polyvinyl alcohol) was investigated in suppression of the soil dust emissions in construction sites in Seoul areas. The efficiency of the two suppressants was tested with test soil sample in a lab-scale wind tunnel box under different concentrations of suppressants and soil textures. Starch and PVA showed the superior ability to suppress soil dust emission as compared to moistening, resulting in PM₁₀ and PM_2.5 lower than the daily limit values of 30 and 15 ㎍/㎥ respectively. PVA showed higher suppression capability than starch for all conditions. The test soils mixed with suppressants also showed dramatically enhanced aggregate stability compared to the non-treated soil.

• Korean Journal of Construction Engineering and Management
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• v.16 no.4
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• pp.30-40
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• 2015

Two-dimensional drawings are widely used as a communication tool in the construction industry, but they are still hard to be understood by engineers with less experience. A four dimensional CAD drawing is presented based on marker-based augmented reality, for visual assistance, detailed information, and prevention of misunderstanding among users. The developed drawing enables the users to easily understand its contents through the functions augmenting components, providing detailed construction information, and simulating construction process, using the marker in a 2D drawing. A questionnaire-based survey validates the capability of the developed drawing that it improves inexperienced engineers' understanding of the drawings.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.14-23
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• 2017

In high-density high-rise cities such as Hong Kong, buildings account for nearly 90% of energy consumption and 61% of carbon emissions. Therefore, it is important to study the design of buildings, especially high-rise buildings, to achieve lower carbon emissions in the city. The carbon emissions of a building consist of embodied carbon from the production of construction materials and operational carbon from energy consumption during daily operation (e.g., air-conditioning and lighting). An integrated analysis of both types of carbon emissions can strengthen the design of low carbon buildings, but most of the previous studies concentrated mainly on either embodied or operational carbon. Therefore, the primary objective of this study is to develop a holistic methodology framework considering both embodied and operational carbon, in order to enhance the sustainable design of low carbon high-rise buildings. The framework will be based on the building information modeling (BIM) technology because BIM can be integrated with simulation systems and digital models of different disciplines, thereby enabling a holistic design and assessment of low carbon buildings. Structural analysis program is first coupled with BIM to validate the structural performance of a building design. The amounts of construction materials and embodied carbon are then quantified by a BIM-based program using the Dynamo programming interface. Operational carbon is quantified by energy simulation software based on the green building extensible Markup Language (gbXML) file from BIM. Computational fluid dynamics (CFD) will be applied to analyze the ambient wind effect on indoor temperature and operational carbon. The BIM-based framework serves as a decision support tool to compare and explore more environmentally-sustainable design options to help reduce the carbon emissions in buildings.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.6
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• pp.555-568
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• 2014

The construction equipment is one of the major sources for hazardous air pollutants in Korea, and the its management has been of great concern recently. The objective of this study was to estimate each contribution of emission of construction equipments according to their production year, electric power consumption and type. To achieve this goal, we developed pollutant emission factors for the machineries manufactured after 2009, which are excluded from the present framework of Korean air pollutants inventory, CAPSS. More than 800 data obtained from emission investigations were utilized for the estimation. Compared with the previous estimation, the scheme used this study was modified to incorporate new emission factors as well as to include the corresponding activity data. Such improvement allow us to gain more detailed emission informations which are better characterized by specifications of construction equipments. The total amount of pollutants emitted from construction equipments in 2011 were estimated as 126.8, 7.0, 58.3, and 17.0 kton for $NO_x$, PM, CO, and VOC, respectively. The estimation results indicate that the increase in the emission of equipments is significantly related to their age and power consumption. The emissions of the older ones manufactured from 1992~1996 were estimated to be the contribution ranged from 23.7% to 26.8%, whereas the newer ones (2009~2011) showed the attributions of 11.3~21.5%. In addition, the results show that the emission of each equipment was increased with the increase in the electric power consumption of engine, probably due to their average output power. Among the nine types of machinery compared, excavators and forklifts were investigated to contribute relatively higher emissions in the level of 39.8~44.0% and 32.0~34.2%, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.787-791
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• 2012

Characteristics of particle separation in water using labscale acoustic standing wave were studied. Acoustic standing wave is similar to either sound wave or ultrasonic, which makes a constant wave while returning to the origin by reflector. During that time, particulates dispersed in water are collected on the node of wave, where a sound pressure is zero. Acoustic standing wave transducer as of 28.0 kHz and 1.0 MHz were utilized and $6.8{\mu}m$ kaolin and $100.5{\mu}m$ redmud in average diameter were used as experimental materials in water. Once acoustic standing wave are generated in water, water temperature rises by $0.15{\sim}0.20^{\circ}C/min$ due to a sound pressure. Initial concentration of kaolin and redmud were controlled to have same as of 0.1, 0.2, 0.3, 0.4, 0.5 g/L, respectively. Removal efficiency of the turbidity in a reacting chamber after 5 minutes, when acoustic sound wave was formed in most distinct, was measured to have 18.2~56.2% for kaolin and 23.0~53.6% for redmud at 1.0 MHz. Particle separation was not observed at 28.0 kHz.

• Land and Housing Review
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• v.4 no.4
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• pp.383-393
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• 2013

The trends of green growth and eco-friendliness came to be the core development indicator for the sustainable global environment. Korean government reflected these trends in the main flows of the national development index, and suggested diverse directions for green construction technologies and high quality construction environment through Third master plan for construction environment. However, the efforts to follow these trends during the construction process as a step for production phrase are not being considered enough yet. In this study, we identified the basic environmental management factors in order to enhance the eco-friendliness of public housing construction sites, and suggested the reasonable conducting parties and process for those respective factors. The results of this study are expected to be the valuable reference in defining the required activities and participants' responsibilities, and improving the work process for systematic on-site environmental management. In applying those results, the discussion should be followed on the executing party of each unit activity and the responsibility assignment for each process. At the same time, the legislation and standard related to environment need to be essentially amended. In the future, the method of evaluating the environmental management activities, and the technical solution to environmental problems are to be reviewed as a further research for successful environmental management.